Hammer for pulverizers



Patented Jan. 25, 1921.

y? LIU] [U [I [I [I [I [I [I D] 7o' 704 fnuentoz M m /SM J. K. BLUM.

HAMMER FOB PULVERIZERS.

APPLICATION FILED DEC; I4, I9I8. 1,366,512.

@y [IIUI [D By lv Atto/megs .l UNITED STATES PATENT oFF-ICE.'

JOSEPH K. BLUM, or `NEW YORK, n. Y.

Appiicatiqii filed December 14, 191s.

To all fw ham t may concern Y ABe it known that I, losnrH K. Bruin'a citizen of the United States, anda resident ofthe city, county,land State of New York have invented certainfnewv and usefulV lin-- provemeiits in Hammers for Pulverizers, of which the following is a specification.

My invention relates to an improvement `in hammers for pulverizing machines, and

can be applied toany rotary hammer pulverizing machine. y invention, moreover, may beembodied in hammers of the bar or Vradial spoke types,. Vsuch as are shown in tions of the hammers toward'the center of the hammer space. My observations have caused by the action ofthe hammers in forcing theirway throughr the loose material. This action Y appears similar to that which o'c'- Vcurs when. forcing a stick through a group of loose stones. The tendency is for the ystones tomove out of the path `of the stickin af direction at right angles to theiline of movement of the stick.` In av similar way, the. stones or material in a crushercrowd toward the casing in a directionv longitudinally ofthe shaft. Thus the material I.crowds inbetween the end portions of the hammer structure and the casing,fwearing off the end portions of the hammer structure As this wear increasesY the distance between the Vends of the hammer structure and the casing, the space for material, increases,-and

the rate of wearaccelerates as it goeson. Consequently, the space between the ends of the hammer structure and the casing increases with undesirable rapidity to the point where the mechanical'eflcienCy is reduced Ato the pointthatvthe renewal of the hammer structure is necessitated. over, the hammers or hammer portionsadjacent the iatsidesorfhea'ds of the casing lthus are forced to operateon a larger body of material with consequent greaterr wear ony rvtheir outer faces than is the-casewith those nearV the center of thel hammer space. The

results of such, uneven radialwear are also highly dsadventegequs -1t1sessentie1 for Specification of Letters Patent.

. parallel to the shaft.

More

inga partof this (disclosure,

HAMMER. ron PULvERrzERs.

Serial No. 266,677.

goodpeiformance that the clearance between the breaking members andi the revolving hammers be uniform, but the uneven wear just mentioned prevents this conditionefrom being maintained. Moreover, for mecha-nr ca l reasons, ythe results of uneven wear cannot to be corrected simply by radial adjustyment ofthe hammers, yalthough it is essential to the satisfactory operation` of the mav.chinesthat this adjustment lbe made. ln

consequence of this, an entireset ofhammers of a given `machine had often, prior to my invention, to yhe discarded while the major Patented Jan. 25; 1921.

portion of the active surfacewas still suit#l able Vfor use, although a set-of new hammers involves a material expense.

*It is, accordingly the principal object of my invention to soV design the 'hammer struclture of aV rotary pulverizer as to prevent as 1 far as possible the accumulation `ofan eX- CSSS 0f Ull'lll being operated on near 'the led me to believe that this uneven wear is ends of the hammer structure.`

A further object of my invention is to Vprovide, hammer structures for. rotary pul` verizersin which the radial Wear shall' be approximately uniform in 'the direction A, final object of my invention isr to providehammer structures for rotary pulver ,izers which shall preventiindue wear on the Vend portions ofthe said structures.,

I ncarrying out the objects just mentioned in accordance with invention, I have constructed `the hammers so that the facesofv the hammers which'look forwardin the direction vof rotation shall be further advanced in the directioniof rotation near` their ends than toward the center.. Points on theradial faces of the hammers which strike the mai [terial thus outline a concaved surface and .thus tend. to force the material toward the center ofthe shaft,.-balan cing the opposite tendency which otherwise would crowd the material toward the flat sides or heads. of.

of hammers embodying my invention.

In the drawing, 'Figure V1 isa partial' view partly in sec- -tion and partly inv elevation, of amaehine of the'bar-ha'mmer type having my inven- @i011 embeded. the@ center, theface 8 Vbeingslightly. concave.k

l Fig. 2 is a detail view of` one of the hammers shown in Fig.1 looking in a direction radially toward the shaft of the machine.

Y Fig. 3 is a partial view in elevation of a 5 machine of the radial hammer type also j having my invention embodied therein.

Fig.` 41 is a detail of a row of radial ham-V merssuch as shown 1n Fig. 3, whenvlewed ential dimension' in passing from" the ends 'i Y of the structure toward the center.

. Fig; 7 is' adetail view looking in a radial direction of a hammer Structure of the radial Y hammertype having my inventionembodied therein, illustratingthe,applicationof the `invention in cases wherey the individual hammers are all` -rectangular andfof the same cross-section; f In the yseparate views the same Ypart is designated bythe same reference character.

Referring tothe drawing in detail, 1 is the` shaftof a 'pulverizing machine of the 'rotary hammer type provided `with acasing having fiat heads'or ends 2. Mounted to rotatewiththe shaft 1 within the heads 2 is a series of disks, such as 3. Hammers, such in said-disksby means of hollowhubs such as 4, surrounding.cylindrical bearing'mem- 'fbers suchjas 5, mounted'. in the disks 3 by `means ofpins such Aas 6. The pins 6 are eccentric to the members VV5 'to permit adjustving thehammers 7 radially of the easing. The mechanical details yheretofore described herein are given simplyV for purposes ofcon-` venience, saidfdetails forming no part of my present invention and being disclosed in 'said Patent l\To.v 1,185,619. As clearly shown in Figs. 1 and 2, the radialactive A fac'esf lofthe hammers 7, which strike the materlal, project Vforwardfarther infthe directlon of rotation at the ends 9 that at the The Vmaterial .consequently Vis urged ltoward the center offthehammers sufliciently" to counteract its normalftendency to move in the 'opposite direction',V Y c Referring more particularly' toFig.` 5 it will be 1seen that the hammer structure 7a illustratedtherein' has radial faces ofstepped formation "presenting shoulders such i as 141 165 which run 1n the radial direction on the ac- Y Fig. 5 is a detail view looking in a-'radialil v'interm'ediate each pair of hammers 10 in' a as 7 of the bar .type are Vpivotallymounted travel toward the center.

tive face of the hammer. The faces of the individual steps are, however, flat in the axial direction, as appears in the ligure. It will be seenthat-the circumferential dimension of this type ofhammer decreases in passing'v from the ends of the hammer to the center, thus tending to -draw the Ymaterial away;v from the ends in thev same manner as the form shown in Fig. 2, since material rebounding'from a corner tends -to fly toward' the center.

In Figs. 3 and 4, I have shown my invention as applied to the hammer of a machine such as shown in Patent 1,125,137. In such machines, the hammers, such as `10, are of radial or spoke form and are `pivoted in rows to pins'or bolts such as `11, suitably mounted parallel to the rotary shaft 12.V In this ty ae of machine there is a space, lsuch as 13,

given ronT approximately., of the same dimension parallel to the shaftV as the individual hammers. However, the sametendency ofthe material to accumulateat Vthe ends of the rows is present in vthis type offmachine also, and the results are vsimilar to those in the type first discussed. I find that this Vdifficulty can be overcome in case of the radial type hammer byV arrangements broadly similarY to those previously described for the U-type hammer. As clearly' shown in FigggsBv and 4, the active faces of Vtheindividual hammers of each longitudinal vrow of radiajl'o'r spoke hammers can be Y shaped so that they Vform sectionsof a concare surface, the portions ofthe radial active faces of the hammers nearest thejcasing 'projecting farther forward in the direction of rotation than the p'ortionsfnearest the center of the row.: In other words, if the 1 05 hammers were arranged in juxtaposition in the row, twithout appreciable spaces between,

the radial active surface Wouldbe substantially the same when viewed in the direction `leokingradially toward the shaft asin the form shown in Figs.A 1 and 2.

Y v Referring `more particularly to Fig. 6, this figure illustrates a Vhammer structure L composed of hammers Vsuchv as 10i of the yradial spoke type, each of which is of rectangular cross-section. n In order to obtain the effect of dr av vin,f 1;V the material away from the ends o-f the structure, the individual hammers are of successively decreas- Vingv circumferential dimension in passing 120 from the endsto the 'center of the structure, `so that the material rebounding from the outside corner of a. hammer is'partially cut off by the hammer to the'outside of the point of rebound, `whilematerial Vrebounding from the inside corner 'of a'hamme'r is freevto The active faces of the'harnmers 10a areflat in the axial d irection as vshown in the 'gure. r

' Int'he'forms shown Figs. 1 and 2,`Figs. 13o

KV terials. l prefer that the radialactive face of a hammer structure embodying my invention should, when viewed radially of the 3 and 4, Fig. 5 and Fig. 6, the hammer structures are made symmetrical with respect to a radial plane through the shaft of the machine, so that they may be reversed in operation, but this is not necessarily the case as cumferential direction at the center than at the ends on one side Aof fthe structure. This is owing to the fact that the individual hammers such as 10b are of the same cross-section along the entire lengthk of the structure, the recess in the center of one face or side of the structure being produced simply by angular .adjustment o f the individual hammers 10b with respect to their axis. In this form of the invention, also, the active faces of the hammers are shown as straight or flat in the axial direction.

In a hammer structure according to my invention, there will be a space between a straight edge laid along theradialface of the structure parallel to the shaft and the radial active'surface near the center thereof. The Vamount of this'distance, which is Vthe measure of concavity, depends upon the hardness and elasticity of the material and `may be as small as c of an inch for a ham-- mer structure twelve inches along the shaft if intended for use 1n pulverizing soft mashaft, outline a parabola, since this form of surface gives the most advantageous rebound.

It will be seen that all the forms of hammer'- structure according to my invention, as shown in vthe drawing, are substantially symmetrical withl respect to the central transverse plane thereof. Vhile not essential, this is the preferred arrangement.

Having thus described my invention, I claim:

l. A hammer structure for rotary hammer pulverizing machines, extending longitudinally of the aXes of rotation and having radial active areas on opposite faces thereof, said radial active areas projecting farther forward in the direction of rotation at the ends than at the center of the structure.

2. A. hammer structure for rotary pulverizing machines, in which the thickness of the hammer body between two adjacent radial surfaces is less at the radius through the center of the aXis of rotation than at the ends of the structure. Y

3. A hammer stiiictiire for rotary hammer pulveriziiig machines, the radial active surfaces of which when viewed radially of the a-Xis of rotation of the structure, have points defining a parabolic curve the ends .of which extend forward in the direction of rotation as comparedto the center.

1l. Jpulverizing machine comprising, in

combination, a casing and a swingingrotary JOS. K. BLUM 

